Write a routine in MATLAB which sets up the tridiagonal matrix as in
class example for the 2-point BVP for some given N=10. Compute the
spectral radius and condition number of that matrix in MATLAB (ask me
how if you do not know). 

(What does Gershgorin theorem tell us ? If you do not know it, ask
me).

Now change N and plot the dependence on N of spectral radius,
condition number, and ... the time it takes to compute them.